Biological signal measurement device, method, and non-transitory storage medium storing program

1 . A biological signal measurement device, comprising:

a processor configured to:

acquire a biological signal related to a beat of a heart of a subject from a biometric sensor;

detect a feature related to the beat of the heart from the biological signal acquired;

compare a change amount of the feature detected per unit time with a threshold defined in first threshold information set in advance, and determine an abnormal change has occurred in the feature when the change amount decreases below the threshold defined in the first threshold information;

set an operation mode of the biometric sensor to a continuous operation mode when it is determined that the abnormal change has occurred in the feature;

set the operation mode of the biometric sensor to an intermittent operation mode in periods when no abnormal change is determined;

determine that the feature has returned to a normal range when the feature satisfies a second threshold information set in advance;

monitor an abnormal duration from a time when the abnormal change has occurred, the abnormal duration being a duration of the continuous operation mode, and changes the operation mode of the biometric sensor from the continuous operation mode to the intermittent operation mode when the duration exceeds a period set in advance;

reset the abnormal duration and change the operation mode to the intermittent operation mode when it is determined that the feature has returned to the normal range while in the continuous operation mode; and

change the operation mode to the intermittent operation mode when the abnormal duration exceeds a preset period.

2 . The biological signal measurement device according to claim 1 , wherein

the processor is further configured to determine the abnormal change in the feature has occurred when a change amount of the feature per unit time exceeds a second threshold defined in the first threshold information.

3 . The biological signal measurement device according to claim 1 further comprising

the processor is configured to;

determine a change of the feature to be within a normal range based on the feature detected and second threshold information set in advance, and

change the operation mode of the biometric sensor to the intermittent operation mode when the feature has changed to be within the normal range in a state where the operation mode of the biometric sensor is set to the continuous operation mode.

4 . The biological signal measurement device according to claim 1 , wherein

the processor further detects, as the feature of the biological signal, any of pulse wave velocity in a blood vessel, heart rate of the heart per unit time, and a feature of a pulse wave.

5 . The biological signal measurement device according to claim 1 , wherein the processor is further configured to generate and output notification information for notifying the subject of the abnormal change in the feature.

6 . A non-transitory storage medium storing a program that causes a processor provided in the biological signal measurement device according to claim 1 to execute processing the biological signal measurement.

7 . The biological signal measurement device according to claim 4 further comprising

the processor configured to generate and output notification information for notifying the subject of the abnormal change in the feature in response to a result of the abnormal change in the feature.