Biological information measurement device

A biological information measurement device comprising:

• an internal pressure controller that increases an internal pressure of a compression band wrapped around a part of a living body, maintains the internal pressure at an avascularization pressure at which the part of the living body is subjected to avascularization, and then lowers the internal pressure to a hold pressure at which avascularization is released;
• a time-series data acquisition unit that acquires time-series data of a volume and the internal pressure of the compression band while the internal pressure of the compression band increases or decreases;
• a relationship deriving unit that derives a relationship between the volume and the internal pressure of the compression band based on the time-series data;
• a first fitting unit that fits a first function to the relationship in a range in which the internal pressure is higher than a diastolic blood pressure of the living body;
• a second fitting unit that fits a second function to the relationship in a range in which the internal pressure is equal to or higher than a predetermined pressure higher than the hold pressure and equal to or lower than the diastolic blood pressure;
• a vascular volume acquisition unit that acquires, as a vascular volume, a difference between a value of the first function at the hold pressure and a hold volume that is a value of the second function at the hold pressure;
• a change amount acquisition unit that acquires an amount of change in the internal pressure of the compression band after the internal pressure of the compression band reaches the hold pressure;
• and
• a dilation rate deriving unit that derives a dilation rate of a vascular diameter or the vascular volume of the living body based on the hold pressure, the hold volume, the vascular volume, and the amount of change in the internal pressure.

A biological information measurement device comprising:

• an internal pressure controller that increases an internal pressure of a compression band wrapped around a part of a living body, maintains the internal pressure at an avascularization pressure at which the part of the living body is subjected to avascularization, and then lowers the internal pressure to a hold pressure at which avascularization is released;
• a time-series data acquisition unit that acquires time-series data of a volume and the internal pressure of the compression band while the internal pressure of the compression band increases or decreases;
• a relationship deriving unit that derives a relationship between the volume and the internal pressure of the compression band based on the time-series data;
• a fitting unit that fits a function to the relationship in a range in which the internal pressure is higher than a diastolic blood pressure of the living body;
• a vascular volume acquisition unit that acquires, as a vascular volume, a difference between a value of the function at the hold pressure and a hold volume that is a volume at the hold pressure in the relationship;
• a change amount acquisition unit that acquires an amount of change in the internal pressure of the compression band after the internal pressure of the compression band reaches the hold pressure;
• and
• a dilation rate deriving unit that derives a dilation rate of a vascular diameter or the vascular volume of the living body based on the hold pressure, the hold volume, the vascular volume, and the amount of change in the internal pressure.