Blood pressure information measurement device

A blood pressure information measurement device for measuring blood pressure information by detecting an arterial volume, comprising:

• a cuff to be wound around a predetermined measurement site;
• adjustment portions that adjust internal pressure of the cuff by increasing or reducing the pressure;
• pressure detection portions that detect a cuff pressure showing the internal pressure of the cuff;
• and
• a volume detection portion that is disposed in a predetermined position of the cuff and that detects arterial volume signals showing the arterial volume,
• wherein the volume detection portion comprises a plurality of pairs of first and second sensors, further including comprising:
• driving control portions for that gradually increase or reduce the cuff pressure until the cuff pressure reaches a specific pressure value by controlling driving of the adjustment portions;
• and
• detection process portions that perform a process that detects a pair of sensors for measurement among the plurality of pairs of the first and second sensors,
• wherein the process performed by the detection process portions includes comprises:
• a step of obtaining volume pulse waves by obtaining arterial volume signals from the volume detection portions for each combination of the plurality of pairs of the first and second sensors in parallel with the control performed by the driving control portion:
• a step of extracting specific volume values in points where an amount of volume change becomes maximal for each volume pulse wave corresponding to the combinations when the cuff pressure has reached the specific pressure value by the driving control portions;
• and
• a step of determining a combination of the first and second sensors in which at least one of a relationship between the specific volume value and a first volume value at a point of time when the cuff pressure becomes a value corresponding to a maximum arterial blood pressure satisfies a predetermined first relationship, and a relationship between the specific volume value and a second volume value at a point of time when the cuff pressure becomes a value corresponding to a minimum arterial blood pressure satisfies a predetermined second relationship, as sensors for measurement, and
• wherein the blood pressure information measurement device further comprises a blood pressure information calculation portion that measures the blood pressure information by using the sensors for measurement determined in the step of determining the sensors for measurement.