Sphygmomanometer, blood pressure measurement method, and computer-readable recording medium

A sphygmomanometer that performs blood pressure measurement by temporarily compressing a measurement target site by a blood pressure measurement cuff, the sphygmomanometer comprising:

• a pump that supplies a fluid to the cuff to pressurize the cuff;
• a pressure sensor that detects a pressure of the cuff;
• a first valve for regular measurement that is fluid-communicatively connected to the cuff and discharges the fluid from the cuff to depressurize the cuff during blood pressure measurement;
• a second valve for emergency exhaust that is fluid-communicatively connected to the cuff and discharges the fluid from the cuff to depressurize the cuff when an abnormality occurs in which discharge of the fluid by the first valve is not normally performed;
• a blood pressure measurement unit that controls operations of the pump and the first and second valves on a basis of the pressure of the cuff output from the pressure sensor to measure a blood pressure of the measurement target site;
• and
• an abnormality determination unit that performs a determination process of determining whether or not there is an abnormality in an emergency exhaust function, wherein
• the abnormality determination unit is configured to, prior to the blood pressure measurement by the blood pressure measurement unit, supply the fluid to the cuff by the pump in a state where a closing instruction is given to the first valve and an opening instruction is given to the second valve, and,
• if the pressure of the cuff becomes equal to or higher than a first reference pressure within a first reference time from a start of driving of the pump, determine that the second valve is abnormal and that there is an abnormality in the emergency exhaust function, whereas if the pressure of the cuff remains lower than the first reference pressure until the first reference time elapses from the start of driving of the pump, determine that there is no abnormality in the emergency exhaust function regardless of whether the first valve is normal or abnormal, and
• the blood pressure measurement unit is configured to, upon start of blood pressure measurement, supply the fluid to the cuff by the pump in a state where closing instructions are given to both the first valve and the second valve, and,
• if the pressure of the cuff does not become equal to or higher than a second reference pressure within a second reference time from the start of driving of the pump, determine that a measurement error has occurred.