Patent US 5,447,162

An electronic Sphygmomanometer employing both the Korotkoff method and the oscillometric method which is thereby capable of accurately measuring blood pressure due to the advantages of the two methods. The electronic sphygmomanometer is arranged in such a manner that either of the results of measurements of the two methods can be automatically selected. A gate for detecting the Korotkoff sound by using an oscillation in cuff pressure is automatically stopped, and the validity of the Korotkoff sound is determined in accordance with a change in the height of the oscillating pulse wave.