Electronic sphygmomanometer and method for determining atrial fibrillation in an electronic sphygmomanometer

An electronic sphygmomanometer that measures blood pressure based on a pulse wave of an artery passing through a site to be measured, the electronic sphygmomanometer comprising:

• a cuff configured to be worn on the site to be measured;
• a pump and a valve each fluidly connected to the cuff;
• a pressure sensor configured to detect a pressure of the cuff;
• and
• a processor,
• wherein, in a normal blood pressure measurement mode, the processor is configured to:
• act as a cuff pressure control unit to perform control to pressurize the cuff by supplying fluid from the pump to the cuff or depressurize the cuff by discharging fluid from the cuff through the valve while acquiring, from the pressure sensor, a cuff pressure signal representing the pressure of the cuff;
• act as a blood pressure measurement unit to extract a pulse wave signal representing a pulse wave superimposed on the cuff pressure signal and to measure blood pressure based on the pulse wave signal;
• act as a pulse wave interval calculation unit to obtain, for each one measurement occasion of a subject, a data group representing pulse wave intervals based on the pulse wave signal obtained from only one blood pressure measurement performed in one pressurization process or one depressurization process;
• wherein each one measurement occasion is an occasion for blood pressure measurement in which the subject wears the cuff once on the site to be measured, and is selected from one morning measurement occasion, one daytime measurement occasion belonging to a time period different from the morning measurement occasion, or one nighttime measurement occasion belonging to a time period different from the morning and daytime measurement occasions;
• act as a first determination unit to aggregate data groups for three or more measurement occasions of the subject and to determine whether or not there is a possibility that atrial fibrillation has occurred based on whether or not irregular pulse wave data exceeding a predetermined allowable range with respect to an average value of the pulse wave intervals exists in the aggregated data groups;
• wherein the three measurement occasions are selected from the morning measurement occasion, the daytime measurement occasion, and/or the nighttime measurement occasion, and every time interval between neighboring measurement occasions in date and time order among the three measurement occasions is within one day as a predetermined allowable period;
• wherein the electronic sphygmomanometer has, under control of the processor, the normal blood pressure measurement mode in which blood pressure measurement is performed only once per one measurement occasion, and an atrial fibrillation screening mode in which blood pressure measurement is repeated three or more times per one measurement occasion;
• and
• wherein, in the normal blood pressure measurement mode, the processor is configured to:
• act as a second determination unit to determine whether or not the irregular pulse wave data in the aggregated data groups satisfies a predetermined frequent occurrence condition based on presence or absence of occurrence of an irregular pulse wave for each one measurement occasion;
• and
• act as a notification unit to provide a notification prompting switching from the normal blood pressure measurement mode to the atrial fibrillation screening mode when the frequent occurrence condition is satisfied.