Automatic sphygmomanometer

An automatic sphygmomanometer for measuring blood pressure of a subject based on Korotkoff sound signals generated during pressurization using a cuff, comprising:

• cuff pressure detecting means for detecting cuff pressure and outputting a cuff pressure signal including a pulse signal component;
• Korotkoff sound detecting means for detecting Korotkoff sounds and outputting Korotkoff sound signals;
• Korotkoff sound signal processing means for performing amplifying and filtering processing based on the Korotkoff sound signals to produce processed Korotkoff sound signals and for comparing the processed Korotkoff sound signals with a predetermined threshold value to obtain extracted Korotkoff sound signals which exceed the predetermined threshold value;
• blood pressure determining means for determining systolic blood pressure and diastolic blood pressure based on the extracted Korotkoff sound signals;
• range setting means for setting ranges based on a transition of the pulse signal component of the cuff pressure signal, the ranges including a range in which systolic blood pressure of the subject is capable of residing and a range in which diastolic blood pressure of the subject is capable of residing;
• evaluating means for providing an indication of whether the systolic and diastolic blood pressures determined by said blood pressure determining means reside in the ranges set by said range setting means;
• and
• display means for displaying information indicative of the systolic and diastolic blood pressures determined by said blood pressure determining means and the indication made by said evaluating means.