Pulse wave detection device, biological information measurement device, and control method for pulse wave detection device

A method for controlling a pulse wave detecting device, the pulse wave detecting device including:

• a sensor section in which a plurality of element rows each including a plurality of pressure detecting elements arranged in a first direction are arranged in a direction perpendicular to the first direction;
• an air bag that presses the sensor section against a body surface of a living body in a state where the first direction crosses a direction of extension of an artery below the body surface;
• and a rotation drive section that rotates the sensor section about each of two axes perpendicular to a pressing direction of the air bag, the two axes being a first axis extending in the first direction and a second axis perpendicular to the first direction, the method comprising:
• a storage control step of storing, in a storage medium, pressure signals detected by the pressure detecting elements in a state where a first rotation angle of the sensor section about the first axis is controlled to a first value, a second rotation angle of the sensor section about the second axis is controlled to a second value, and the sensor section is pressed against the body surface by the air bag;
• and
• a rotation angle determining step of determining the second value based on the pressure signals detected by the plurality of pressure detecting elements included in a selected element row corresponding to one element row selected from the plurality of element rows in a state where the sensor section is pressed against the body surface by the air bag, performing control of the second rotation angle to the second rotation value by using the rotation drive section, and determining the first value based on the pressure signals detected by the pressure detecting elements under the control,
• wherein in the rotation angle determining step, processing for increasing a pressing force applied to the sensor section against the body surface by the air bag is performed and one element positioned on the artery out of the pressure detecting elements included in the element rows is successively determined, as a target element, during increase of the pressing force, based on a pressure signal group detected by the pressure detecting elements of the element rows, and an element row having shortest elapsed time from start of the increase to time when a signal level of an AC component of a pressure signal detected by the successively determined target element reaches, after reaching a maximum value, a threshold value specified with reference to the maximum value and smaller than the maximum value, is selected as the selected element row among the plurality of element rows.

A non-transitory computer-readable storage medium, which stores a control program for a pulse wave detecting device, the pulse wave detecting device including:

• a sensor section in which a plurality of element rows each including a plurality of pressure detecting elements arranged in a first direction are arranged in a direction perpendicular to the first direction;
• an air bag that presses the sensor section against a body surface of a living body in a state where the first direction crosses a direction of extension of an artery below the body surface;
• and a rotation drive section that rotates the sensor section about each of two axes perpendicular to a pressing direction of the air bag, the two axes being a first axis extending in the first direction and a second axis perpendicular to the first direction, the control program causing a computer to execute:
• a storage control step of storing, in a storage medium, pressure signals detected by the pressure detecting elements in a state where a first rotation angle of the sensor section about the first axis is controlled to a first value, a second rotation angle of the sensor section about the second axis is controlled to a second value, and the sensor section is pressed against the body surface by the air bag;
• and
• a rotation angle determining step of determining the second value based on the pressure signals detected by the plurality of pressure detecting elements included in a selected element row corresponding to one element row selected from the plurality of element rows in a state where the sensor section is pressed against the body surface by the air bag, performing control of the second rotation angle to the second value by using the rotation drive section, and determining the first value based on the pressure signals detected by the pressure detecting elements under the control,
• wherein in the rotation angle determining step, processing for increasing a pressing force applied to the sensor section against the body surface by the air bag is performed and one element positioned on the artery out of the pressure detecting elements included in the element rows is successively determined, as a target element, during increase of the pressing force, based on a pressure signal group detected by the pressure detecting elements of the element rows, and an element row having shortest elapsed time from start of the increase to time when a signal level of an AC component of a pressure signal detected by the successively determined target element reaches, after reaching a maximum value, a threshold value specified with reference to the maximum value and smaller than the maximum value, is selected as the selected element row among the plurality of element rows.